Self adjusting track extension

ABSTRACT

In a storage and retrieval system of the type having a plurality of aisles in which an article handling load carrier operates and a transfer car for transferring the load carrier between the aisles for operation in several of the aisles, track extensions are pivotally mounted to the transfer vehicle and a plurality of camming and support surfaces are positioned adjacent the rails at the ends of the aisles. A camming surface is also positioned on the end of the track extensions opposite their pivotal attachment to the transfer vehicle and, as the transfer vehicle is moved between the respective aisles, the camming surfaces move into alignment with each other to position the supporting surfaces of the adjustable track extensions in continuous and substantially coplanar relationship with the rails on the transfer vehicle and in the individual aisles.

United States Patent 1191 Busam 1451 May 15, 1973 {54] SELF ADJUSTINGTRACK EXTENSION Primary Examiner-Gerald M. Forlenza [75] Inventor:Donald H. Busam, Hometown, lll. Amsmm Exammer8' Johnson 1 Attorney- A.W. Mol1nare,et al. [73] Assignee: lnterlake Inc., Chicago, Ill.

[22] Filed: Dec. 30, 1971 57 ABSTRACT [21] Appl. No.: 213,981 In astorage and retrieval system of the type having a plurality of aisles inwhich an article handling load [52] CL ZN/16A B, 104/48 14/7], carrieroperates and a transfer car for transferring the 246/] load carrierbetween the aisles for operation in several 51 Int. Cl. ..B6Sg 35/00,365g 1/06 of the aisles hack extehshhs are Pimtahy h [58] Field ofSearch .12l4/l6.4 B, 38 BA; the transfer vehicle and PhhahtY of cammhgand 104/48; 14/7] support surfaces are positioned adjacent the rails atthe ends of the aisles. A camming surface is also posi- [56] ReferencesCited tioned on the end of the track extensions opposite their pivotalattachment to the transfer vehicle and, as UNITED STATES PATENTS thetransfer vehicle is moved between the respective 1 556 294 10/1928Meehan ..104/4s aisles the cammingsurfaces move alignment with 3:593:8237 1971 Thompson ..2l4/l6.4 B each other the Supporting Surfaces of theadjustable track extensions in continuous and substantially coplanarrelationship with the rails on the transfer vehicle and in theindividual aisles.

13 Claims, 4 Drawing Figures PATENTEDMAYYI 5 ms SHEET 1 [IF 2 INVENTOR.DUN/11D H BUS/4M BY 777 4 ATTORNEYS PATENTEU v 3,732,992

SHEEI 2 OF 2 DONALD BUS/4M M/W,

ATTORNEYS 1 SELF ADJUSTING TRACK EXTENSION BACKGROUND AND SUMMARY OF THEINVENTION This invention relates to a self adjusting track extensionand, more particularly, to a self adjusting track extension in anarticle storage and retrieval system which includes an article handlingvehicle or load carrier and a transfer vehicle for transferring the loadcarrier between the aisles of the system.

In mechanized storage and retrieval systems, it is frequentlyadvantageous to transfer the article handling load carrier of the systembetween the various aisles of the storage frames in which the articlesare stored in and retrieved from. Such transfer between aisles minimizesthe cost of such systems, the load carriers employed in such systemsfrequently being large and expensive components of the system. In orderto effect transfer of the load carrier between aisles, various transfervehicle constructions and arrangements have been employed in the past inwhich a transfer vehicle is movable transversely of the aisles and whichis adapted to supportably receive the load carrier thereon during thetransfer operation. Due to the size of the load carriers and transfervehicles of such systems, these vehicles are frequently designed to runupon rails, the transfer vehicle upon rails which extend transversely ofthe ends of the aisles, the load carrier upon rails which extendlongitudinally in the aisles and also upon rails upon the support bed ofthe transfer vehicle which are alignable with the aisle rails. Thetransfer vehicle rails enable movement and positioning of the loadcarrier upon the transfer vehicle bed from the aisles for transfer ofthe load carrier.

In order to effect smooth movement of the load carrier, both onto andoff of the transfer vehicle, the aisle rails, as well as the transfervehicle bed rails, must be capable of accurate alignment with eachother, so that when the transfer vehicle is positioned adjacent theaisle from which the load carrier is to be received from or to bedischarged to, the vehicle supporting surfaces of these respective railsare accurately aligned in elevation with the corresponding surfaces ofthe rails in the aisles. Such elevational alignment in the prior systemshas been time consuming and expensive, both in the establishment andsetting of alignment tolerances during the initial installation of thesystem, as well as in the subsequent maintenance of these alignmenttolerances. This is particularly the case where the storage andretrieval system is large and extensive in size. To achieve acceptablealignment, not only must the transfer vehicle bed rails be capable ofaccurate elevational alignment with respect to each and every given oneof the rails in the aisles in which it is intended to operate the loadcarrier, but where the system includes more than one transfer vehicle,the bed rails of each vehicle must be both initially aligned andsubsequently periodically checked and realigned with each of these aislerails. In addition, after the passage of time, differential floorsettling likely will occur, requiring frequent realignment to maintainthe alignment tolerance relationships of the original installation,whether one or several transfer cars are employed in the system.

When practicing the principles of the present invention, accurateelevational alignment of the transfer vehicle bed rails and the aislerails may be readily, easily,

inexpensively and automatically realized in both large and small systemsandin which there are a few or many aisles in which the load carrier ofthe system is to be operated. When practicing the principles of thepresent invention, not only is initial alignment of these railssimplified, but the adverse effects on such alignment due todifferential floor settling over a period of time are minimized. In thepresent invention, a self adjusting supporting extension is contemplatedwhich, when the transfer vehicle is positioned adjacent a desired aisle,will automatically align in continuous and substantially coplanarrelationship its supporting surface with the supporting surfaces of thetransfer vehicle and the aisles of the system.

In a principal aspect of the present invention, a self adjusting memberis provided for supporting a first vehicle during transfer of thevehicle to and from a second vehicle. The self adjusting membercomprises an elongate member having a supporting surface thereon whichextends the length of the member and pivotal mounting means adjacent oneend of the member mounts the member for pivotal movement. Cam means onthe member, spaced from the pivotal mounting means, is constructed andarranged to cam the supporting surface of the elongate member about itspivot axis.

In another principal aspect of the invention, a self adjusting transferarrangement for supportably transferring a first vehiclebetween a secondvehicle and a given surface includes elongate means having a supportingsurface thereon which is extendible between a support surface of thesecond vehicle and the given sur face when the latter surfaces arepositioned adjacent each other. Pivotal mounting means adjacent one endof the elongate means mounts the elongate means for pivoting about apivot axis which is substantially parallel to the direction of movementof the second vehicle and cam means, spaced from the pivot axis, urgesthe supporting surface of the elongate means into continuousrelationship with the support surface of the second vehicle and thegiven surface when the second vehicle is positioned adjacent the givensurface.

In another principal 'anotherprincipal aspect of the invention, .anarticle storage and retrieval system includes a plurality of storageframes separated by a plurality of aisles, and a transfer vehicle whichismovable across an end of the aisles for transferring a load carrierwhich is normally operable in the aisles between several of the aislesfor operation. In this system, the improvement includes self adjustingmeans for supporting the load carrier during movement onto and off ofthe transfer vehicle. The self adjusting means includes elongate meanshaving a supporting surface thereon which extends between the aislesurfaces and the support surfaces of the transfer vehicle and pivotalmounting means adjacent one end of the elongate means for pivotallymounting the latter about a pivot axis which is substantially parallelto the direction of movement of the transfer vehicle between the ends ofthe aisles. Cam means is associated with the elongate means and arespaced from the pivotal mounting means toward the other end of theelongate means for urging a supporting surface of the elongate meansinto continuousrelationship with the load carrier supporting surfaces ofthe aisles and the transfer vehicle when the transfer vehicle ispositioned adjacent to and in alignment with the ends of the aisles.

These and other objects, features and advantages of the presentinvention will be more clearly understood through a Consideration of thefollowing detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS In the course of this description,reference will frequently be made to the attached drawings in which:

FIG. 1 is a plan view of a part of an article storage and retrievalsystem of the type employing a load carrier and transfer vehicle andwhich includes a preferred embodiment of self adjusting track extensionincorporating the principles of the present invention;

FIG. 2 is a partial, enlarged cross sectioned side elevation view of thesystem taken along line 2 2 of FIG. 1 and showing, in further detail, apreferred embodiment of self adjusting track extension of the presentinvention;

FIG. 3 is a further enlarged exploded view of the preferred embodimentof self adjusting track extension of the present invention; and

FIG. 4 is a partial side elevation view of another embodiment of selfadjusting track extension constructed in accordance with the principlesof the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the preferred embodiments ofthe present invention, a self adjusting track extension facilitates themovement ofa first vehicle onto and off of the supporting bed of asecond vehicle. Such vehicles, may be, for example, the vehicles in anarticle storage and retrieval system in which the first vehiclecomprises a load carrier which is movable longitudinally in aislesbetween a plurality of storage frames in which the articles are to bestored in and retrieved from, and the second vehicle comprises atransfer vehicle or car which is movable transversely of the ends of theaisles and upon which the load carrier may be supportably received anddischarged from, such that the load carrier may be moved for operationfrom one of the aisles to another of the several aisles in the system.

Referring particularly to FIG. 1, a simplified version of such storageand retrieval system is shown which includes a plurality of storageframes and 10 which are spaced from each other by an aisle 12. A loadcarrier 14, shown in dot and dash outline only in FIG. 1, is supportedand movable upon one or more rails 16 and 16' which extendlongitudinally in the aisle 12. Thus, the load carrier 14 is movableupon wheels on rails 16 and 16 in the aisle for the storage andretrieval of articles in selected ones of the storage frames 10. Theload carrier 14,which may be quite large in size and quite expensive, ispreferably transferable for operation between aisle l2 and other givenaisles (not shown) which are parallel to aisle 12 in the storage systemin order to minimize the overall expense of the installation byincreasing the versatility and range of operation of a given loadcarrier.

In order to effect the transfer of the load carrier 14, a transfervehicle or car 18 is provided which is movable on two or more rails 20and 20' which extend transversely of the ends of the respective aisles16. The upper surfaces of each of the rails 20 and 20 define supportsurfaces 22 which supportably receive the wheels 24 of the transfervehicle thereon. Thus, the transfer vehicle 18 may be selectively movedinto alignment with a selected one of the aisles 12 in order to receiveor discharge the load carrier 14 from or to the rails 16 and 16' of therespective aislesfSince the load carrier 14 is to be supportablypositioned upon the support bed 26 of the transfer vehicle 18 duringtransfer between the aisles, the support bed 26 of the transfer vehiclepreferably includes a plurality of rigid support beams 27 and 28 uponwhich spaced supporting rails 30 and 30' are supported. These railsextend across the transfer vehicle in a direction parallel to andalignable with the aisle rails 16 and 16', respectively, to receive thewheels of the load carrier 14 thereon, the upper support surfaces 31 ofthe aisle rails 16 being as close to coplanar as is possible with theupper support surfaces 32 of the bed rails 30. The storage and retrievalsystem thus far described is conventional and will not be described infurther detail, since the specific constructional details of thetransfer vehicle, the storage frames and the load carrier form no partof the present invention, except as hereafter described, a wide varietyof such components being readily available and which may be selectivelychosen by one of ordinary skill in the art.

An important feature of the present invention resides in the selfadjusting supporting member or track extension which automaticallyinsures the continuity of alignment of the surfaces 31 and 32 of theaisle rails 16 and 16' and the support bed rails 30 and 30 which, inturn, enables smooth and rapid movement of the load carrier between theaisles and the transfer vehicle when the vehicle is to be transferredfor operation between aisles. In the present invention, the transfervehicle bed 26, and specifically the beam 27 adjacent the ends of theaisles, is spaced somewhat from the aisle ends 34 of the respectiveaisles 12. A pair of track extensions 36 and 36' span this distancebetween the spaced ends 37 and 38 of rails 16 and 16' and 30 and 30,respectively. Since the track extensions 36 and 36 are substantiallyidentical in construction, extension 36 will be described in detailonly.

The track extension 36 comprises an elongate substantially rigid member40 which extends between the end 37 of the aisle rail 16 and the end 38of the transfer car rail 30. Member 40 includes an upward facing supportsurface 42 which, as hereafter will be described, is automaticallypositioned to extend between the surfaces 31 and 32 of the aisle and thetransfer car rails, respectively, and in continuous and substantialcoplanar relationship with these respective surfaces. A pair of rigidplates 44 are firmly affixed, such as by welding, to the sides and atone end 46 of the member 40. These plates 44 form a part of a pivotalmounting structure and project beyond the end 46 of the member at whichpoint each of the plates includes a substantially circular apertured cutout 48 for receipt of a hinge pin 50.

Firmly affixed to the side beam 27 of the transfer vehicle adjacent theends of the aisles and storage frames, are a pair of spaced rigidmounting blocks 52. The hinge pin 50 comprises a rigid, substantiallycylindrical shaft 53 having a pair of flattened ends 54 for preventingrotation of the shaft in the final assembly. The diameter of thecylindrical portion 53 is substantially equal to the diameter of thecircular cut outs 48 and the pin is slipped through the cut outs asshown in FIG. 3. After mounting the pin in the cut outs, the pin withits now pivotally mounted track extension 36, is firmly fixed to theside beam 27 of the transfer vehicle, for example by way of bolts 56which extend through apertures 58 in flattened ends 54 of the shaft,through apertures 60 in the mounting blocks 52, and into the web 61 ofthe Ibeam which defines support bed beam 27 adjacent the ends of theaisles, thus mounting the pin 50 and blocks 52 in the open channel 62which faces the aisles and which is defined between the beam flanges 63and 64. Preferably bolts 66 also extend upward through apertures 68 inthe pin and apertures in the flange 63 of beam 27 to further lock thepin 50 against rotation. In addition, suitable apertured shim p'acks,such as packs 69 and 70 may be provided to adjust the pivot axis of thetrack extension either horizontally or vertically and to insure adequatepivotal freedom and alignment of the surface 42 adjacent end 46 of theextension 36 with surface 32 of rail 30, respectively.

A support assembly 72 is rigidly fixed to the floor 74 of theinstallation adjacent the ends of the aisle rails 16 and the step 76 inthe floor, as shown in FIG. 2. This support assembly 72 comprises amounting block 78, which may be bolted to the floor with bolts 79, and acam block 80, which may be bolted by bolts 81 onto member 78. Cam block80 includes a convex upward facing camming and supporting surface 82, aportion 83 of which is at maximum elevation above the floor 74 andhaving a pair of inclined surfaces 84 extending downward therefrom inthe direction of transverse movement of the transfer vehicle between theaisles.

A complementary camming member 86 is firmly affixed, as by welding, tothe elongate member 40 in spaced relationship to the pivot axis providedby pin 50 and preferably at the other end 88 of the elongate memberopposite the pivot axis. This camming member 86 also includes a convexcurved camming surface 90 which faces downward toward the cammingsurface 82 of the cam block 80. Surface 90 includes a portion 92 ofminimum elevation above the floor 74 and a pair of upwardly inclinedsurfaces 94 which extend upward from each side of the latter portion inthe direction of movement of the transfer vehicle 18.

During movement of the transfer vehicle it will be seen that theportions 83 and 92 of the curved surfaces 82 and 90, respectively, willbecome substantially vertically aligned with each other and contact eachother such that the surface 83 of member 80 will supportably positionthe surface-42 of the track extension 36 with the surface 31 of theaisle rail 16 in continuous relationship with each other. To insureaccurate alignment continuity of surface 42 with each of the individualaisle rail surfaces in the various aisles, each of the respective camblocks 80 at the ends of the aisle rails are preferably suitablyshimmed, as by shim packs 96, such that the elevational distance betweenthe surfaces 83 of the-various cam blocks 80 and the surfaces 31 oftheir aisle rails 16 is substantially equal to the distance between thesurfaces 92 and 42 of the track extensions. Thus, even though theelevation of floor 74 may vary between the aisles or the floor uponwhich the transfer vehicle may settle subsequent to installation,surfaces 31 and 42 will always be accurately aligned in continuousrelationship with each other. 1

After considering the above description of the preferred embodiment ofthe present invention, its operation should be evident. However, forpurposes of clarity a brief description of the operation of theinvention follows.

It will be first assumed'that the load carrier 14 is presentlypositioned in one of the aisles (not shown) and it is desired totransfer the load carrier to another aisle 16 for operation. The loadcarrier 14, preferably under its own power, will be driven toward theend of the aisle in which it is presently located and thence out of theaisle and onto the support bed 26 of the transfer vehicle 18 to theposition as shown in the dot and dash lines in FIG. 1. This transitionbetween the aisle and transfer vehicle is smooth, since the wheels ofthe load carrier, as they leave the ends 37 of the aisle rails 16 and16, will be supported upon the surfaces 42 of the elongate trackextensions 36 which have been accurately positioned in continuoussubstantially coplanar alignment and in transverse alignment with theaisle rail before the load carrier was enroute to the transfer vehicle.

Once the load carrier 14 has been positioned upon the transfer vehicleas shown in FIG. 1, the transfer vehicle will be driven transversely ofthe aisles by suitable drive means, such as the motor 981 shown in FIG.1, toward aisle 16 in which it is desired to operate the load carrier,the track extensions 36 and 36' being carried along with the transfervehicle, since they are mounted thereto. As the transfer vehicleapproaches the aisle 16 in which it is desired to operate the loadcarrier, the left end 88 of the track extensions, as viewed in FIG. 2,will approach the camming and support surfaces 82 of the cam blocksadjacent the ends 37 of the aisle rails and the convex camming surfaceof the camming member 86 will contact the convex camming surface 82.Further movement of the transfer vehicle into alignment with the aisle16, will cause the elongate members 40 to pivot about the pivot axisprovided by pin 50, such that the support surface 42 of the elongatemembers will be cammed by the curved surfaces 82 and 90 from theposition shown in the dot and dash lines in FIG. 2 upward to the solidposition shown in FIG. 2, wherein surfaces 31, 42 and 32 are all incontin uous and substantial coplanar relationship with each other. Whenthe elongate members 36 and the aisle rails 16 have been accuratelyaligned with each other in both the horizontal and vertical, thetransfer vehicle will be stopped and the load carrier will be operated,preferably under its own power, so as to move off of the transfervehicle and onto the aisle rails 16 of the aisle 12 in which it is tooperate. During discharge of the load carrier across the spanning trackextensions 36 and 36', the elongate members will be firmly supportedupon their hinge pins 50 at their one end 48 and at their other end bythe mounting block 78 and cam block 80, since surface 92 will bevertically aligned with and rest upon surface 83 of the cam block,having been cammed there by the coaction of the inclined surfaces 84 and94.

Referring to FIG. 4, another embodiment of support assembly 72' is shownin which the cam block 80 is mounted to the end of the aisle rail 16,rather than upon the mounting block 78 as in the embodiment of FIGS.l-3. In this embodiment, plate 99 is firmly attached to the cam block80, either by casting integrally therewith or attaching thereto by othersuitable means. Plate 99 extends horizontally beneath the surface 31 ofrails 16 and is firmly fixed to the web 100 of rail 16, as by welding.Such integral formation of the cam block 80 with the rail eliminates theneed for subsequent reshimming of the support assembly 72', since thedistance between the camming surfaces 82 of this integrally formedassembly and the surfaces 31 of the aisle rails will always be fixedeven though settling of the floor might occur.

Upon considering the above description of the invention, it will beevident that a simple and inexpensive self adjusting track extension isprovided in accordance with the principles of the invention which willautomatically, and by a camming action, adjust for differences inelevation between the aisle supporting surfaces of each of theindividual respective aisles in which the load carrier is to be operatedand this critical alignment between the rails of the respective aislesand the transfer car is easily, inexpensively and reliably achieved.Moreover, the self adjustable track extension of the present inventionmay be advantageously employed where the storage and retrieval systemincludes more than one transfer vehicle, since variations between thesevehicles is readily compensated for by the present invention. Inaddition, the need for realignment due to subsequent floor settlementand rail wear is substantially reduced and, if such realignment doesbecome necessary, it may be readily achieved simply by reshimming eitherpin 50 or the support assemblies 72 as necessary. Also settlement of thetransfer vehicle rails and 20 or the aisle rails 16 and 16' relative toeach other will automatically be compensated by the self adjusting trackextension of the invention. Although such settlement will displace theplanes of the transfer car rail surfaces 32 from the aisle rail surfaces31, these surfaces and the supporting surface 42 of the track extensionwill still remain continuous and smooth transfer of the load carrierthereby continuous to occur.

It should be understood that although the track extensions of thepreferred embodiments of invention have been shown as preferably beingmounted for pivotal movement upon the transfer vehicle and upon one sideof that vehicle only, that the extensions of the invention may bereversed such that a plurality of members are pivotally mounted adjacentthe respective ends of the various aisle rails and the camming surfacesare carried upon the transfer vehicle and the extensions may also extendfrom both sides of the transfer vehicle. Although mounting of theextensions adjacent the aisle rail ends is possible, the preferredembodiment is that which has been described in which the extensions arepivotally mounted to the transfer car, since such arrangement minimizesthe number of extensions which must be provided. In addition, cammingsurfaces which cam the extensions into continuous relationship inresponse to movement of the transfer car in its transverse direction arepreferred, since the complexity and expense of such arrangement isminimized, although it will be understood that the extensions could bepowered outward of the transfer vehicle and into position once thetransfer vehicle has been aligned with the aisles by employing suitablehydraulic or other power operated cylinders.

ltshould be understood that the embodiments of the present inventionwhich have been described are merely illustrative of a few of theapplications of the principles of the invention. Numerous modificationsmay be made by those skilled in the art without departing from the truespirit and scope of the invention.

What is claimed is:

l. A self adjusting transfer arrangement for supportably transferring afirst vehicle between a second vehicle and a given surface, comprising:

a support surface on said second vehicle for supporting the firstvehicle when said first vehicle is positioned thereon,

means for moving said second vehicle in a given direction,

elongate means having a supporting surface thereon, said supportingsurface of said elongate means being extendible between said supportsurface of said second vehicle and said given surface when the lattersurfaces are positioned adjacent each other,

pivotal mounting means adjacent one end of said elongate means pivotallymounting said elongate means about a pivot axis which is substantiallyparallel to said given direction of movement of said second vehicle, and

cam means spaced from said pivot axis for urging said supporting surfaceof said elongate means into continuous relationship with said supportsurface of said second vehicle and said given surface when said secondvehicle is positioned adjacent said given surface.

2. The arrangement of claim 1 wherein said pivotal mounting means mountssaid elongate means upon said second vehicle for movement with thelatter and said cam means is positioned adjacent said given surface.

3. The arrangement of claim 1 wherein said cam means comprises:

support means stationarily mounted relative to one of said given surfaceand second vehicle and having a curved support surface, said curvedsupport surface comprising a portion of maximum elevation and at leastone portion extending downward from said maximum elevation portion andin a direction substantially parallel to said given direction ofmovement of said second vehicle, and

a camming member on said elongate means having a curved camming surfacethereon elevationally alignable with said curved support surface, saidcurved camming surface comprising a portion of minimum elevation and atleast one portion extending upward from said minimum elevation portionin a direction substantially parallel to said given direction ofmovement of said second vehicle, one of said curved surfaces beingmovable into elevational alignment with the other when said secondvehicle is moved into said position adjacent said given surface, wherebysaid supporting surface of said elongate means is cammed into saidcontinuous relationship with said given surface.

4. The arrangement of claim 3, wherein said portion of minimum elevationof said curved camming surface is substantially aligned in the verticalwith and rests upon said portion of maximum elevation of said curvedsupport surface during transfer of said first vehicle between saidsecond vehicle and said given surface.

5. The arrangement of claim 3, wherein said support means isstationarily fixed adjacent said given surface and said elongate meansis pivotally mounted upon said second vehicle for movement therewith.

6. The arrangement of claim 3 including shim means for positioning atleast one of the supporting surface of said elongate means in thehorizontal adjacent said support surface of second vehicle, thesupporting surface of said elongate means in the vertical relative tosaid support surface of said second vehicle, and said supporting surfaceof said elongate means in the vertical relative to said given surface.

7. The arrangement of claim 1 wherein said support surface on saidsecond vehicle, said elongate means and said given surface each compriserails.

8. The arrangement of claim 1 wherein said supporting surface of saidelongate means is urged by said cam means into said continuousrelationship in response to movement of said second vehicle into aposition adjacent said given surface.

9. In an article storage and retrieval system having a plurality ofstorage frames for the storage of articles therein, a plurality ofspaced aisles between said frames having support surfaces therein forsupporting a load carrier for operation therein, and a transfer vehiclehaving a support surface thereon for supporting the load carrier, saidtransfer vehicle being movable across an end of the aisles andselectively alignable with the respective aisles for transferring theload carrier between several of the aisles for operation therein, theimprovement in said system including in combination therewith selfadjusting means for supporting said load carrier during movement thereofbetween said aisles and said transfer vehicle, said self adjusting meanscomprising:

elongate means having an upward facing supporting surface thereon, saidsupporting surface of said elongate means extending between said aislesupport surfaces and the support surface of said transfer vehicle,

pivotal mounting means adjacent one end of said elongate means forpivotally mounting said elongate means about a pivot axis which issubstantially parallel to the direction of movement of said transfervehicle between the ends of the aisles, and cam means associated withsaid elongate means and spaced from said pivotal mounting means towardthe other end of said elongate means for urging said supporting surfaceof said elongate means into continuous relationship with at least one ofsaid support surface of said transfer vehicle and said aisles when saidtransfer vehicle is positioned adjacent to and in alignment with theends of said aisles.

10. The system of claim 9 wherein said elongate means is pivotallymounted upon said transfer means for movement therewith across the endsof the aisles, and said cam means comprises:

support means stationarily mounted adjacent the ends of each of saidaisles and having an upward facing curved camming and support surfacethereon, and

a camming member on and movable with said elongate means and having adownward facing curved camming surface thereon, said camming surface ofsaid camming member being movable into elevational alignment with saidcamming and support surface of said support members when said transfervehicle is moved into alignment with said aisles to pivot said elongatemeans about said pivotal mounting means and urge said supporting surfaceof said elongate means into continuous relationship with said supportsurface of said aisles and said transfer vehicle.

11. The system of claim 10 wherein said elongate means and said supportsurface of said aisles and transfer means comprise rails.

12. The system of claim 9 wherein said load carrier and said transfervehicle are floor running.

13. The system of claim 9 wherein said supporting surface of saidelongate means is urged by said cam means into said continuousrelationship in response to movement of said transfer vehicle into aposition adjacent said ends of said aisles.

CERTIFKIATE OF Pat'entNo 7322992 7 I Dated y 1973 DQNALD H. BUSAMInventor(s) It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

I' a i In claim 1, line 16; after or", automatically is inserted; andline 18, after "continuous", elevational is inserted.

In claim 9, 'line 36, after "for", automatically isinserted; and

, line Z, after "Continuous", elevational is inserted.

Signed and sealed this 25th day of December 1975.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. Attesting Officer RENE D. TEGTMEYER ActlngCommissioner of Patents

1. A self adjusting transfer arrangement for supportably transferring afirst vehicle between a second vehicle and a given surface, comprising:a support surface on said second vehicle for supporting the firstvehicle when said first vehicle is positioned thereon, means for movingsaid second vehicle in a given direction, elongate means having asupporting surface thereon, said supporting surface of said elongatemeans being extendible between said support surface of said secondvehicle and said given surface when the latter surfaces are positionedadjacent each other, pivotal mounting means adjacent one end of saidelongate means pivotally mounting said elongate means about a pivot axiswhich is substantially parallel to said given direction of movement ofsaid second vehicle, and cam means spaced from said pivot axis forurging said supporting surface of said elongate means into continuousrelationship with said support surface of said second vehicle and saidgiven surface when said second vehicle is positioned adjacent said givensurface.
 2. The arrangement of claim 1 wherein said pivotal mountingmeans mounts said elongate means upon said second vehicle for movementwith the latter and said cam means is positioned adjacent said givensurface.
 3. The arrangement of claim 1 wherein said cam means comprises:support means stationarily mounted relative to one of said given surfaceand second vehicle and having a curved support surface, said curvedsupport surface comprising a portion of maximum elevation and at leastone portion extending downward from said maximum elevation portion andin a direction substantially parallel to said given direction ofmovement of said second vehicle, and a camming member on said elongatemeans having a curved camming surface thereon elevationally alignablewith said curved support surface, said curved camming surface comprisinga portion of minimum elevation and at least one portion extending upwardfrom said minimum elevation portion in a direction substantiallyparallel to said given direction of movement of said second vehicle, oneof said curved surfaces being movable into elevational alignment withthe other when said second vehicle is moved into said position adjacentsaid given surface, whereby said supporting surface of said elongatemeans is cammed into said continuous relationshiP with said givensurface.
 4. The arrangement of claim 3, wherein said portion of minimumelevation of said curved camming surface is substantially aligned in thevertical with and rests upon said portion of maximum elevation of saidcurved support surface during transfer of said first vehicle betweensaid second vehicle and said given surface.
 5. The arrangement of claim3, wherein said support means is stationarily fixed adjacent said givensurface and said elongate means is pivotally mounted upon said secondvehicle for movement therewith.
 6. The arrangement of claim 3 includingshim means for positioning at least one of the supporting surface ofsaid elongate means in the horizontal adjacent said support surface ofsecond vehicle, the supporting surface of said elongate means in thevertical relative to said support surface of said second vehicle, andsaid supporting surface of said elongate means in the vertical relativeto said given surface.
 7. The arrangement of claim 1 wherein saidsupport surface on said second vehicle, said elongate means and saidgiven surface each comprise rails.
 8. The arrangement of claim 1 whereinsaid supporting surface of said elongate means is urged by said cammeans into said continuous relationship in response to movement of saidsecond vehicle into a position adjacent said given surface.
 9. In anarticle storage and retrieval system having a plurality of storageframes for the storage of articles therein, a plurality of spaced aislesbetween said frames having support surfaces therein for supporting aload carrier for operation therein, and a transfer vehicle having asupport surface thereon for supporting the load carrier, said transfervehicle being movable across an end of the aisles and selectivelyalignable with the respective aisles for transferring the load carrierbetween several of the aisles for operation therein, the improvement insaid system including in combination therewith self adjusting means forsupporting said load carrier during movement thereof between said aislesand said transfer vehicle, said self adjusting means comprising:elongate means having an upward facing supporting surface thereon, saidsupporting surface of said elongate means extending between said aislesupport surfaces and the support surface of said transfer vehicle,pivotal mounting means adjacent one end of said elongate means forpivotally mounting said elongate means about a pivot axis which issubstantially parallel to the direction of movement of said transfervehicle between the ends of the aisles, and cam means associated withsaid elongate means and spaced from said pivotal mounting means towardthe other end of said elongate means for urging said supporting surfaceof said elongate means into continuous relationship with at least one ofsaid support surface of said transfer vehicle and said aisles when saidtransfer vehicle is positioned adjacent to and in alignment with theends of said aisles.
 10. The system of claim 9 wherein said elongatemeans is pivotally mounted upon said transfer means for movementtherewith across the ends of the aisles, and said cam means comprises:support means stationarily mounted adjacent the ends of each of saidaisles and having an upward facing curved camming and support surfacethereon, and a camming member on and movable with said elongate meansand having a downward facing curved camming surface thereon, saidcamming surface of said camming member being movable into elevationalalignment with said camming and support surface of said support memberswhen said transfer vehicle is moved into alignment with said aisles topivot said elongate means about said pivotal mounting means and urgesaid supporting surface of said elongate means into continuousrelationship with said support surface of said aisles and said transfervehicle.
 11. The system of claim 10 wherein said elongate means and saidsupport surface of said aisles and transfer means coMprise rails. 12.The system of claim 9 wherein said load carrier and said transfervehicle are floor running.
 13. The system of claim 9 wherein saidsupporting surface of said elongate means is urged by said cam meansinto said continuous relationship in response to movement of saidtransfer vehicle into a position adjacent said ends of said aisles.